To someone who’s spent the last few years thinking about the American food chain, a visit to Manhattan’s Union Square in the spring of 2006 feels a little like a visit to Paris in the spring of 1968 must have felt, or perhaps closer to the mark, Peoples Park in Berkeley in the summer of 1969. Not that I was in either of those places at the appointed historical hour, or that the stakes are quite as high.

Walking with a loaded rifle in an unfamiliar forest bristling with the signs of your prey is thrilling. It embarrasses me to write that, but it is true. I am not by nature much of a noticer, yet here, now, my attention to everything around me, and deafness to everything else, is complete. Nothing in my experience has prepared me for the quality of this attention. I notice how the day’s first breezes comb the needles in the pines, producing a sotto voce whistle and an undulation in the pattern of light and shadow tattooing the tree trunks and the ground.

We are seated in the back of a four-wheel-drive van, bouncing across a hypergreen cow pasture, our palms pressed against the roof to keep from flying, when Spot jams on the brakes. Spot is a burly, moonfaced twentysomething from Seattle who fiercely loves Kauai, his adopted island. He works as a guide for an outfitter in Poipu, taking small groups into the forest to leap off waterfalls and soar across rivers on zip lines—the two implausible adventures our son, Isaac, has persuaded us we need to attempt on this particular afternoon.

Carbophobia, the most recent in the centurylong series of food fads to wash over the American table, seems to have finally crested, though not before sweeping away entire bakeries and pasta companies in its path, panicking potato breeders into redesigning the spud, crumbling whole doughnut empires and, at least to my way of thinking, ruining an untold number of meals.

Late last summer, I moved from Zone 5 to Zone 9, or, to be both more and (at least to a gardener) less geographically precise, from southern New England to Northern California. We gardeners divide the world into zones of plant hardiness; the lower the number, the colder it gets; so to go from Zone 5, with winter lows reaching 20 below, to Zone 9, where it barely freezes, is, horticulturally speaking, tantamount to a change of planet. I’ve been gardening seriously for 25 years and have learned all sorts of things, yet I feel as if I now have to start from zero.

Americans have been talking a lot about trade this campaign season, about globalism’s winners and losers, and especially about the export of American jobs. Yet even when globalism is working the way it’s supposed to—when Americans are exporting things like crops rather than jobs—there can be a steep social and environmental cost.

It’s hard to say whether an American hamburger was appreciably less safe to eat the day after a Holstein cow tested positive for bovine spongiform encephalopathy in Washington State last month than it was the day before, but it had sure gotten less appetizing. The news cracked open a door on the industrial kitchen where America’s meat is prepared, and what we glimpsed on the other side was enough to send even the heartiest diner to the vegetarian entree or the fish special.

Sometimes even complicated social problems turn out to be simpler than they look. Take America’s “obesity epidemic,” arguably the most serious public-health problem facing the country. Three of every five Americans are now overweight, and some researchers predict that today’s children will be the first generation of Americans whose life expectancy will actually be shorter than that of their parents. The culprit, they say, is the health problems associated with obesity.

When I was a kid growing up in the early 60’s, anybody could have told you exactly what the future of food was going to look like. We’d seen “The Jetsons,” toured the 1964 World’s Fair, tasted the culinary fruits (or at least fruit flavors) of the space program, and all signs pointed to a single outcome: the meal in a pill, washed down, perhaps, with next-generation Tang.